Status:
Active
Health advisory:
200515
Date Issued:
15 May 2020
Issued by:
Dr Angie Bone, Deputy Chief Health Officer (Environment), Victoria
Issued to:
General Practitioners, Hospital Emergency Departments and other health professionals

Key messages

  • Carbon monoxide is an odourless, colourless gas that may cause symptoms including tiredness, shortness of breath, headaches, dizziness, nausea, weakness, confusion or chest pain if inhaled. Symptoms can be mistaken for a flu-like illness. Very high levels of carbon monoxide can be fatal.
  • This winter many Victorians are at home for longer periods due to the current circumstances of coronavirus (COVID-19) and may be running gas heaters for longer periods than usual.  This could increase the risk of accidental carbon monoxide poisoning if domestic gas heaters are not regularly maintained, or operated without adequate ventilation (fresh air). 
  • If carbon monoxide poisoning is suspected, turn off all gas appliances and fans, open windows and doors, leave the property and seek medical advice.
  • Medical professionals should:
    • exercise a high level of suspicion if similar symptoms are occurring in other members of the household, and the person reports feeling better when away from the house. People and pets may become unwell at the same time.
    • test for carboxyhaemoglobin levels in any person with suspected carbon monoxide poisoning
    • notify the Environmental Health Unit, Department of Health and Human Services on 1300 761 874 of any cases of confirmed carbon monoxide poisoning in the home
  • Energy Safe Victoria recommends that all gas heaters are serviced at least once every two years by a qualified gasfitter. Some models of open-flued gas space heaters are subject to a safety alert and must be rectified as well as serviced before use https://esv.vic.gov.au/safety-alerts/gas-open-flued-gas-heaters/. Installing a carbon monoxide alarm is a useful back-up measure but does not replace the need for regular servicing of gas heaters.
  • Before using a gas heater, check that any permanent ventilation in your home is clear and ensure there is fresh air flow into the room. Under certain conditions such as inadequate ventilation or running bathroom exhaust fans or kitchen rangehoods at the same time as an open-flued space heater can result in negative pressure which draws carbon monoxide into the room instead of discharging outside through the flue or chimney. 
  • Gas heating should not be left running continuously overnight or for extended periods.
  • Portable outdoor gas appliances should never be used indoors. Heat beads produce carbon monoxide and should never be used inside for cooking or heating purposes.

What is the issue?

Any gas heater can spill carbon monoxide – including old and new heaters, central heating units, space heaters and wall furnaces and decorative appliances such as decorative log fires. 

To avoid this risk, all gas heaters and decorative log fires need to be serviced at least every two years by a qualified gasfitter. A qualified gas fitter checks the installation including testing for carbon monoxide leakage.

The use of open-flued gas space heaters, especially models on the Energy Safe Victoria's safety alert list may produce increased indoor carbon monoxide levels under certain conditions. If the heater is not operating properly, the combination of inadequate ventilation, as well as operating bathroom exhaust fans or kitchen rangehoods at the same time as this type of gas heater, may draw unsafe levels of carbon monoxide into living areas. The risk is further increased if the heater and associated components such as the flue are not regularly serviced/checked. 

People may visit general practitioners or emergency departments with health concerns about potential carbon monoxide exposure from domestic gas heating. 

Who is at risk?

All Victorians using a gas heater or decorative log fire that has not been regularly serviced or is operated with inadequate ventilation. Children, pregnant women and unborn babies, older people and those with chronic illnesses are at increased risk from carbon monoxide exposure.

Symptoms

Carbon monoxide is an odourless, colourless gas that may cause symptoms including tiredness, shortness of breath, headaches, dizziness, nausea, weakness, confusion or chest pain if inhaled. 

Anyone experiencing any of these symptoms should:

  • immediately turn off all gas appliances (heater, stove) and kitchen rangehood or bathroom fans
  • open the doors and windows to ventilate the area
  • leave the property, keeping the doors and windows open if possible
  • seek medical advice immediately or call NURSE-ON-CALL on 1300 60 60 24 (24/7). In an emergency call 000. 

Diagnosis

Diagnosis can often be challenging as symptoms are similar to many other ailments that are common in winter, such as viral infections and flu. Health care workers should exercise a high level of suspicion if similar symptoms are occurring in other members of the household, and if the patient reports feeling better when outside the house. Carboxyhaemoglobin levels and symptoms will decrease when the patient is removed from the carbon monoxide source or when they receive high-flow oxygen. 

The diagnosis of carbon monoxide poisoning is therefore based on history and examination, in conjunction with an elevated carboxyhaemoglobin level determined by using pulse CO-oximetry and/or blood gas analysis. Measure carboxyhaemoglobin levels in any case of suspected carbon monoxide poisoning when the patient is first seen. 

Advise the Environmental Health Unit, Department of Health and Human Services on 1300 761 874 of all elevated results. The department works with Energy Safe Victoria to investigate the source of the carbon monoxide and ensure that the affected person’s home gas appliances are safe for carbon monoxide emissions.

Recommendations

Regular maintenance of gas heaters (at least every two years) is the best way to reduce the possibility of carbon monoxide poisoning in your home. For more information go to esv.vic.gov.au/carbon-monoxide 

Do not use the following open flued gas space heaters which are subject to a safety alert from Energy Safe Victoria, unless these heaters have been rectified and serviced by a qualified gasfitter.

To check whether you have an open-flued gas space heater, contact the manufacturer for advice or check with your local gasfitter.  

Everyone should:

  • continue to service all gas heaters and decorative log fires at least once every two years irrespective of make, model or age 
  • be aware of the symptoms of carbon monoxide exposure and actions to take in the event of suspected carbon monoxide poisoning
  • consider installing an audible carbon monoxide alarm that meets US or EU standards (see below).
  • check on neighbours, family and friends to ensure awareness of safety precautions to prevent carbon monoxide poisoning from gas heating during the cooler months.

Carbon monoxide alarms can be a useful back-up precaution but should not be considered a substitute for the proper installation and maintenance of gas heating appliances. If you are considering whether to purchase one or more audible carbon monoxide alarms:

  • select alarms that meet US or EU carbon monoxide standards, including recommendations for use and installation. To identify these alarms, either the packaging or the alarm will indicate that it complies with one of the following standards:
    • UL2034 (US) or
    • EN50291 (EU)
  • select audible alarms that indicate when the sensor has expired
  • while these alarms may provide some indication of carbon monoxide gas levels, the readings are limited to the location where the sensors are placed and levels elsewhere in the room may vary.
  • follow the manufacturer’s instructions provided on installation, maintenance and use.

Do not bring outdoor gas appliances inside such as a patio heater or barbeque. This is dangerous and could also lead to carbon monoxide poisoning.

More information

Clinical information

For more information about diagnosing carbon monoxide poisoning - Think carbon monoxide (The Medical Journal of Australia)

Consumer information

Energy Safe Victoria: Heating your home with gas   
Better Health Channel: Gas heating - health and safety issues 

Contacts

Clinicians should notify the Environmental Health Unit, Department of Health and Human Services on 1300 761 874 of any cases of confirmed carbon monoxide poisoning.

Public housing tenants with gas heating can contact the Department’s Housing hotline on 1800 148 426 for information.

Other consumers with open-flued gas heater models on the Energy Safe Victoria alert safety list need to contact the supplier (or manufacture) for servicing. For Pyrox or Vulcan Heritage gas heaters call the manufacturer, Climate Technologies on (03) 8795 2462.

Anyone experiencing symptoms that may be due to carbon monoxide exposure should seek medical advice or call the NURSE-ON-CALL on 1300 60 60 24 (24/7). In an emergency call 000.